1. Field of the Invention
The present invention relates to a surface pressing button, and an electronic device including the surface pressing button, such as an audio device or a video device.
2. Description of the Prior Art
An electronic device such as an audio device or a video device includes many surface pressing buttons to perform operations of the electronic device, on a front surface in many cases. In case that the electronic device is a DVD (Digital Versatile Disc) player, it includes surface pressing buttons capable of performing operations such as power ON/OFF, playback, stop, and disc ejection, so that the operation related to the surface pressing button can be performed by pressing the surface pressing button.
FIG. 6 is a front view showing a DVD player which is an example of a conventional electronic device. A DVD player PM shown in FIG. 6 includes a slot Ih for a DVD medium, a power supply button 91p, a stop button 91a, a playback (pause) button 91b, a medium ejection button 91c to eject the DVD medium, and a front panel 92 on which the aforementioned buttons are provided.
FIG. 7A is a sectional view showing a push button of the electronic device shown in FIG. 6 and FIG. 7B is a sectional view showing a mounting part of the electronic device shown in FIG. 6. As shown in FIGS. 7A and 7B, the surface pressing button 91 is arranged so that a surface pressing part 911 may penetrate a through hole 921 formed in the front panel 92. Each of the four surface pressing buttons 91 includes the surface pressing part 911, a switch pressing part 912 integrally formed with the surface pressing part 911, and a supporting part 913 to support the surface pressing part 911 and the switch pressing part 912.
The supporting part 913 includes a boss hole 914 to which a boss 922 of the front panel 92 which will be described later is inserted, and a hinge 915 which is connected to the surface pressing part 911 and supported so as to be cantilevered. As shown in FIGS. 7A and 7B, the supporting part 913 supports the four surface pressing buttons 91 arranged in line through the hinges 915. An inclination preventing part 916 integrally formed with the supporting part 913 to prevent the surface pressing button 91 from inclining is formed between both ends and the adjacent surface pressing buttons 91. The boss hole 914 is also formed at the distal end of the inclination preventing part 916.
At this time, the boss 922 penetrates the boss hole 914 formed in the supporting part 913. An end of the boss 922 penetrating the boss hole 914 is heated to be fused and welded together to be fixed to the boss hole 914.
A substrate 93 is provided on the side of the switch pressing part 912 of the surface pressing button 91, and a switch 94 is also provided on the side of the switch pressing part 912. The switch 94 is mounted on the substrate 93 and a small space is formed between the switch 94 and the switch pressing part 912.
When the surface pressing button 91 presses the surface pressing part 911, the hinge 915 of the supporting part 913 bends, and an end of the switch pressing part 912 is moved downward. The switch 94 is arranged in the moving direction of the end of the switch pressing part 912. Thus, when the switch pressing part 912 is moved downward, the switch 94 is pressed by the switch pressing part 912.
When the surface pressing button 91 is pressed by strong force, the switch 94 receives a large load from the switch pressing part 912 and it could be damaged. In order to prevent the strong force from being applied to the switch 94, the front panel 92 includes a hook 923 to prevent an end opposite to the hinge 913 of the surface pressing part 911 from being moved too much. The hook 923 is formed adjacent to the through hole 921 as shown in FIG. 7A. The hook 923 is integrally formed with the front panel 92. When the hook 923 engages with the surface pressing part 911, the surface pressing part 911 and the switch pressing part 912 are prevented from being turned.
When the surface pressing part 911 of the surface pressing button 91 is pressed, the surface pressing part 911 and the switch pressing part 912 are turned around the hinge 913 for a certain amount and then the end of the surface pressing part 911 comes into contact with the hook 923 and it is stopped. Thus, a large load is prevented from being applied to the switch 94.
Japanese Unexamined Utility Model Publication No. 06-9023 (1994) discloses that a stopper rib is formed on a switch knob and, when the switch knob is pressed, the stopper rib abuts on a substrate holder to restrict an operation of the switch knob.
Japanese Unexamined Patent Publication No. 2004-39324 discloses that a stopper is provided on each side of a pressing part and, when a button is pressed, the stopper comes into contact with a substrate and prevents the button from being pressed more than needs.
The surface pressing button 91 includes the supporting part 913 and the boss hole 914 formed at the distal end of the inclination preventing part 916 which extends from the supporting part 913. When the surface pressing button 91 is mounted on the front panel 92, the boss 922 is inserted into the each boss hole 914. However, since the hook 923 which engages with the surface pressing part 911 to restrict the movement of the surface pressing part 911 is mounted on a position close to the through hole 921 in the front panel 92, when the surface pressing button 91 is mounted, the surface pressing part 911 comes into contact with the hook 923 also, so that it is difficult to mount the surface pressing button 91 on the front panel 92.
In case that the hook 923 is formed of a material having a certain degree of flexibility, when the surface pressing button 91 is mounted on the front panel 92, the hook 923 is bent and the surface pressing part 911 can easily engage with the through hole 921. However, since the hook 923 is flexible, it cannot support a force applied from the surface pressing part 911 sufficiently in some cases.
Although it may be considered that the hook 923 and the front panel 92 are manufactured separately and after the surface pressing button 91 is mounted on the front panel 92, the hook 923 is mounted, in this case, it is troublesome to mount the hook 923 and the hook 923 cannot support the force applied from the surface pressing button 911 in some cases.
Although it may be considered that lengths of the boss 922 and the boss hole 914 are shortened, some play is provided between the boss 922 and the boss hole 914 and the surface pressing button 91 is tilted when it is mounted, in this case, the surface pressing button 91 could be unstably fixed because the lengths of the boss 922 and the boss hole 914 are shortened.